ES2389125T3 - Procedure for the application of anticorrosive layers on metal surfaces - Google Patents

Abstract

Procedure for the application of anticorrosive layers on metal surfaces, in which a hardenable preparation under atmospheric conditions in a thickness of at least 15 μm is applied on the bare metal surface, previously containing at least 15 a 70% by weight of at least one hardenable binder agent system (A) under atmospheric conditions, - 1 to 70% by weight of at least one component (B), selected from the group of finely divided fillers, pigments or colorants, - 0.1 to 40% by weight of a polymer anti-corrosion agent (C), as well as - 5 to 83.9% by weight of at least one solvent (D), the amounts referring respectively to the total amount of components of the formulation, and in the case of the polymer anti-corrosion system of a copolymer (C), which is constituted by the following monomer components: (C1) 5 to 60% by weight of at least one monomer C on monoethylenic unsaturation, which has at least one, preferably exactly one nitrile group, (C2) 70% by weight of at least one monomer with monoethylenic unsaturation, comprising at least one acidic group, (C3) a 20 a 80% by weight of at least one aromatic hydrocarbon with monoethylenic unsaturation, as well as (C4) optionally 0 to 25% by weight of other monomers with ethylenic unsaturation other than (C1) to (C3), the amount referring respectively to the total amount of monomeric structural units in the copolymer, and subsequent hardening of the layer applied under atmospheric conditions, with atmospheric conditions being understood as hardening temperatures of more than 0 to 40 ° C in the presence of air, and a relative humidity of 10 to 80 %.

Description

Procedure for the application of anticorrosive layers on metal surfaces

The present invention relates to a process for the application of atmospheric anticorrosive layers on metal surfaces, in which copolymers are used which have as monomer components that have nitrile groups, monomers that have acid groups, as well as vinyl aromatic monomers. This also refers to preparations for the application of anticorrosive layers.

Metal objects, components, works or metal constructions consisting of usual metal materials should generally be protected from corrosion. In this case they adopt an essential role in the corrosion protection coatings with which the metal surface is protected from the influence of corrosive media. Suitable coating systems for corrosion protection usually contain one or more binding agents, anti-corrosive pigments, if appropriate organic corrosion inhibitors, as well as other complementary substances and additives.

Various techniques can be used for the application of anticorrosive layers.

In the case of immovable metal constructions, such as buildings, bridges, electric poles, oil tankers, pipelines, thermal power plants or chemical installations, naturally anti-corrosive coatings are applied and sprayed on site. Drying and hardening of such anticorrosive layers is carried out under atmospheric conditions, that is, at room temperature, as well as in the presence of air and normal ambient humidity. This type of anti-corrosion protection is also called atmospheric anti-corrosion protection, often depending on the type of corrosion load, mild, medium or severe anti-corrosion protection.

DE 2365583 and DE 2346651 describe terpolymers consisting of up to 80% by weight of styrene or styrene derivatives, at least 15% by weight of a nitrile monomer with ethylenic unsaturation, and 5 to 35% by weight of an acid monomer with ethylenic unsaturation, which may be neutralized if necessary. Such terpolymers are used as a coating component for cans for food products. For this purpose, the coatings are oven dried for 60 to 90 seconds at a temperature of 205 ° C.

No reference is made to the applicability of such copolymers in atmospheric corrosion protection.

US 3707516 describes a coating composition consisting of 5-50% by weight of film-forming components in an organic solvent. The film-forming components consist of graft polymers with 10.75% by weight of a polymer skeleton, and 9-25% by weight of polymer side chains. The polymer skeleton is constituted by a copolymer of acrylonitrile, methyl methacrylate, styrene, and mixtures thereof, as well as less than 5% by weight of a carboxylic acid with ethylenic unsaturation incorporated by polymerization. This coating composition can be used as a primer or enamel to protect metals against salt corrosion.

JP 55-066940 describes an aqueous coating composition that is dried at room temperature for coating metal surfaces. The coatings show improved chemical stability, weather stability, gloss and adhesion. In this case, a polymer hydrosol is incorporated into a water-soluble resin. The polymer hydrosol consists of particles of a particle size of approximately 0.1 µm, obtained by polymerization of a carboxylic acid with α, β-monoethylenic unsaturation, an alkenyl aromatic monomer, a (meth) acrylate and 30% in weight of another monomer with α, β-monoethylenic unsaturation, for example acrylonitrile.

In the case of the copolymers described herein, they are secondary dispersions. The proportion of these copolymers classified as "additive" with respect to binding agent is between 95: 5 and 55: 45, and therefore constitutes the main component of the coatings.

WO 91/14722 (Henkel, also EP 311906) describes aqueous polyacrylate dispersions or polyacrylate emulsions, obtainable by copolymerization of a monomer bearing at least one carboxyl group, which was neutralized before copolymerization, and at least one other hydrophobic monomer. . The mixture additionally contains an emulsifier, and at least one thickening agent. The composition is used as a coating agent for the temporary protection of hard surfaces.

It was the task of the invention to provide an improved method for the application of anticorrosive layers for atmospheric corrosion protection, as well as to improved anticorrosive agents.

Accordingly, a procedure was found for the application of anticorrosive layers on metal surfaces, in which a hardenable preparation under atmospheric conditions in a thickness of at least 15 µm is applied on the bare metal surface, or containing the preparation at least

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 15 to 70% by weight of at least one hardenable binder agent system (A) under atmospheric conditions,

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 1 to 70% by weight of at least one component (B), selected from the group of finely divided fillers, pigments or dyes,

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 0.1 to 40% by weight of a polymer anti-corrosion agent (C), as well as

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 5 to 83.9% by weight of at least one solvent (D), in the case of the polymer anti-corrosion system of a copolymer (C), which is constituted by the following monomer components:

(C1) 5 to 60% by weight of at least one monomer with monoethylenic unsaturation, which has at least one, preferably exactly one nitrile group,

(C2) 10 to 70% by weight of at least one monomer with monoethylenic unsaturation, comprising at least one acidic group,

(C3) 20 to 80% by weight of at least one aromatic hydrocarbon with monoethylenic unsaturation, as well as

(C4) optionally 0 to 25% by weight of other monomers with ethylenic unsaturation other than (C1) to (C3),

the amount referring respectively to the total amount of monomeric structural units in the copolymer, and subsequent hardening of the layer applied under atmospheric conditions, atmospheric conditions being understood as hardening temperatures of more than 0 to 40 ° C in the presence of air, and a relative humidity of 10 to 80%.

This anticorrosive protection is also effective in small quantities, and is easily miscible with the other components of the coating mass.

The difference in requirements for atmospheric corrosion protection coatings and masses against other anticorrosive conditions is that the coatings have atmospheric corrosion protection have a significantly higher layer thickness than in other applications, and dry and harden at room temperature , so that drying and hardening comprise essentially longer time intervals. In most cases and preferably, the anti-corrosion coating is also applied under atmospheric conditions. During the total time interval, the non-hardened wet layers are vulnerable, for example, against water spray or environmental influences, so that in the coating masses there are clearly different requirements than in other anticorrosive coating masses.

In the case of the invention, it is a process for atmospheric corrosion protection, in which a hardenable binder system is used under atmospheric conditions, and the layer is hardened after application under atmospheric conditions.

In another aspect, the invention relates to formulations for the application of anticorrosive layers, which comprise the copolymers mentioned at the beginning.

Surprisingly it was found that the copolymers according to the invention lead to improved anticorrosive layers for atmospheric corrosion protection. The copolymers give the surface good corrosion protection, good adhesion, and can also significantly improve the mechanical properties of the enamels. By incorporating additional hydroxy and / or amino functionalities, the binding of the copolymers to the binder system can be improved. Additionally, the copolymer has a certain amphiphilic character, that is, it is suitable for stabilizing interfaces, such as metal-enamel, enamel-environment, hydrophobic-hydrophilic interfaces in the enamel.

In particular, the following should be explained regarding the invention.

Copolymer (C)

The copolymer (C) is constituted by the monomers (C1), (C2), (C3), as well as optionally (C4), being able to naturally use several different monomers (C1), (C2), (C3), or optionally (C4), in each case. In addition to (C1), (C2), (C3), and if necessary (C4), no additional monomers are present.

Monomers (C1)

In the case of the monomers (C1) it is at least one monomer with monoethylenic unsaturation, which has at least one, preferably exactly one nitrile group.

Apart from the nitrile group and the monoethylenic unsaturation group, these monomers (C1) preferably do not carry other functional groups.

The number of nitrile groups amounts to 1 to 1, preferably exactly 1.

Examples of (C1) acrylonitrile, methacrylonitrile, fumarodinitrile and maleidinitrile monomers, preferably acrylonitrile or methacrylonitrile, are examples.

In the case of monomer (C1) it is acrylonitrile in a very particularly preferred manner.

The total amount of monomers (C1) together amounts to 5 to 60% by weight according to the invention, based on the total amount of monomer structural units in the copolymer (C). The amount preferably amounts to 5 to 45% by weight, and especially preferably 10 to 35% by weight.

Monomers (C2)

In the case of monomers (C2) these are monomers with monoethylenic unsaturation, which have at least one acidic group. The acid group can be presented as a free acid group, or also completely or partially as a salt.

In the case of the acid groups, it is at least one group selected from carboxyl groups, phosphoric acid groups, phosphonic acid groups and sulfonic acid groups.

Examples of monomers with COOH groups comprise (meth) acrylic acid, vinyl acetic acid, crotonic acid or isocrotonic acid. You can also try monomers with 2 COOH groups. Examples include maleic acid, fumaric acid, methyl fumaric acid, methylmaleic acid, dimethylmaleic acid, as well as, if appropriate, the corresponding cyclic anhydrides. Preferred monomers with COOH groups are (meth) acrylic acid, as well as itaconic acid.

Examples of monomers having phosphoric acid and / or phosphonic acid groups include vinylphosphonic acid, monovinyl phosphate, allylphosphonic acid, monoalyl phosphate, 3-butenylphosphonic acid, (mono-3-butenyl) phosphate, mono- (4) phosphate -vinyloxybutyl), (phosphonoxyethyl) acrylate, (phosphonoxyethyl) methacrylate, mono- (2-hydroxy-vinyloxy-propyl) phosphate, mono- (1-phosphonoxymethyl-2-vinyloxy-ethyl) phosphate, mono- phosphate (3-allyloxy-2-hydroxy-propyl), mono-2- (allyloxy-1-phosphonoxymethyl-ethyl) phosphate, 2-hydroxy-4-vinyloxymethyl-1,3,2-dioxaphosphol or 2-hydroxy-4-allyloxymethyl- 1,3,2-dioxafosfol. As a monomer having phosphoric acid and / or phosphonic acid groups, vinylphosphonic acid is preferred.

Examples of monomers containing sulfonic acid groups include allylsulfonic acid, metalylsulfonic acid, styrene sulfonate, vinyl sulfonic acid, allyloxybenzenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid or 2- (methylacryloyl) ethyl sulfonic acid. As a monomer containing sulfonic acid groups, acrylamido-2-methylpropanesulfonic acid is preferred.

In the case of atmospheric corrosion protection, monomers containing COOH groups and sulphonic acid groups are used as a monomer (C2), itaconic acid is very particularly preferred.

The total amount of monomers (C2) together amounts to 10 to 70% by weight according to the invention, based on the total amount of monomer structural units in the copolymer (C). The amount preferably amounts to 15 to 60% by weight, and especially preferably 20 to 55% by weight.

Monomers (C3)

In the case of the monomers (C3) it is at least one aromatic hydrocarbon with monoethylenic unsaturation.

Examples of such hydrocarbons comprise, in particular, styrene, as well as styrene derivatives, such as α-methylstyrene, 2-vinyltoluene, 4-vinyltoluene or allylbenzene.

Especially preferably it is styrene.

The total amount of monomers (C3) together amounts to 20 to 80% by weight, based on the total amount of monomeric structural units in the copolymer (C). The amount preferably amounts to 30 to 70% by weight, and especially preferably 35 to 65% by weight.

Monomers (C4)

The copolymers (C) used according to the invention may also contain 0 to 25% by weight, preferably 0 to 15% by weight, and especially 0 to 10% by weight of other monomers with ethylenic unsaturation ( C4), which are different from (C1), (C2) and (C3), but are copolymerizable with (C1), (C2) and (C3), as structural units. Such monomers - if necessary - can be used for fine adjustment of the properties of the copolymer (C).

Completely dispensing with an additional monomer (C4) may constitute a preferred embodiment of the present invention.

In the case of monomers (C4) they are monomers with monoethylenic unsaturation other than monomers (C1) to (C3). The specialist makes an appropriate selection regarding the type and quantity of such monomers (C4) according to the desired properties, as well as the desired application of the polymer.

In the case of the monomer (C4) it is preferably a monomer having OH groups. In particular, it can be a hydroxyalkyl ester with 1 to 4 carbon atoms of (meth) acrylic acid, such as, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (1,4-mono-) (meth) acrylate butanediol acrylate. 2-hydroxyethyl acrylate is preferred.

Preferably it can be treated in addition to a monomer having -NH2 groups, or a monomer, which can form -NH2 groups in the case of hydrolysis. An example of such a monomer is N-vinylformamide.

The OH and / or NH2 groups can serve for the best binding of the copolymer (C) with the binder agent system, reacting with appropriate components of the binder agent system.

As long as they are present, the amount of monomers (C4) generally amounts to 0.1 to 25% by weight, based on the total amount of monomeric structural units in the copolymer (C). The amount is preferably from 1 to 15% by weight, especially preferably from 2 to 10% by weight, and most particularly preferably from 3 to 7% by weight.

In the case of monomers (C4), it is possible to deal with cross-linking monomers with two or more double bonds with isolated ethylenic unsaturation. Examples include di-, or poly (meth) acrylates, such as ethylene glycol di (meth) acrylate or butanediol 1,4-di (meth) acrylate, di-, tri- or tetraethylene glycol or tri (meth) acrylate (meth) trimethylolpropane acrylate. However, the copolymers (C) should not be crosslinked to that extent. If crosslinking monomers are present, their amount will generally not exceed 4% by weight with respect to the total sum of monomers, preferably 3% by weight, and especially preferably 2% by weight.

Obtaining copolymers (C)

The preparation of copolymers (C) used according to the invention is preferably carried out by means of radical polymerization. The implementation of a polymerization through radicals, including facilities necessary for this purpose, is known in principle by the specialist. The polymerization is preferably carried out under the use of thermally decomposing polymerization initiators. Preferably peroxides can be used as thermal initiators. However, polymerization can also be carried out photochemically.

Monoalcohols can preferably be used as the solvent. Examples of suitable monoalcohols comprise alkoxy alcohols with 1 to 8 carbon atoms, and especially 2-butoxyethanol (butylglycol), as well as 2-butoxy-propanol.

Further preferred are alkyl alkanoates, alkyl alkanoate alcohols, alkoxylated alkyl alkanoates, and mixtures thereof.

For example, esters are n-butyl acetate, ethyl acetate, 1-methoxypropyl 2-acetate and 2-methoxyethyl acetate, as well as the mono- and diacetylesters of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol or tripropylene glycol, such as butyl glycol acetate.

For example, ethers are tetrahydrofuran (THF), dioxane, as well as dimethyl-, ethyl- or n-butyl ethers of ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol or tripropylene glycol.

Alkanoate alcohols are, by way of example, mono-alkyl ether (C1 to C4) of poly-alkylene glycol (C2 to C3).

Ether alcohols are, by way of example, dialkyl ether (C1 to C4) of poly-alkylene glycol (C2 to C3), dipropylene glycol dimethyl ether, preferably butyl glycol.

In addition, carbonates, such as 1,2-ethylene carbonate, 1,2-propylene carbonate or 1,3-propylene carbonate, are also conceivable.

Radical polymerization with thermal initiators can be carried out at 50 to 200 ° C, preferably 60 to 180 ° C, especially preferably at 80 to 200 ° C, and especially at 100 to 170 ° C. The amount of initiator amounts to 0.1 to 15% by weight, based on the amount of monomers, preferably 3 to 12% by weight, and especially preferably 5 to 9% by weight. As a general rule, an amount of approximately 6% by weight is recommended. The polymerization time is usually 1 to 40 hours, preferably 3 to 25 hours, and especially preferably 5 to 15 hours. If necessary, the copolymers can be isolated from the solvent according to methods known to the specialist.

The acidic groups of the polymer can be neutralized before, during or after the polymerization, also completely, or preferably partially.

Examples of appropriate bases for neutralization comprise in particular mono-, di- and trialkylamines having 1 to 8 linear, cyclic and / or branched carbon atoms, mono-, di- or linear or branched trialkanolamines, especially mono-, di - or trialkanolamines, alkyl ethers with 1 to 8 linear or branched carbon atoms, or mono-, di

or trialkanolamines with 1 to 8 linear or branched carbon atoms, oligo- and polyamines, such as diethylenetriamine.

If neutralization is carried out before or during polymerization, the optimum amount of base is adjusted to the acid monomer used in each case. By means of the degree of neutralization the polymerization can be controlled so that the optimum residual monomer content is obtained. The neutralization is preferably carried out after polymerization.

The organic solutions of modified copolymers obtained can be used directly for the formulation of crosslinkable organic preparations. Naturally, the polymer can also be isolated according to methods known to the specialist. Since in the case of the products obtained, these are solutions and not hydrosols, as for example in JP 55-066940, that is to say dispersed particles, the copolymers according to the present invention are more easily incorporated in coating masses than dispersed particles. .

For incorporation into aqueous formulations, water can be conveniently added to the solution, and the organic solvent removed by methods known to the specialist.

The molecular weight Mw of the copolymer is selected by the specialist according to the desired purpose of use. A MW of 3000 g / mol at 1 000 000 g / mol, preferably 4000 to 200 000 g / mol, and especially preferably 5000 to 100 000 g / mol, has been successful.

Procedure for the application of anticorrosive layers

By means of the process according to the invention, any metal body can be protected in principle from corrosion by treating the metal surface with a preparation comprising at least one hardenable and / or crosslinkable binding agent system (A), a component (B), selected to from the group of finely divided fillers, pigments or dyes, as well as a copolymer (C). The formulation may optionally contain a solvent or a solvent system (D), in which the components are dissolved or dispersed. Preferably a solvent is present.

In principle, all types of metals can be coated. However, it is preferably non-noble metals or alloys, which are commonly used as metallic building materials, and which must be protected against corrosion. Examples especially include iron, steel, zinc, zinc alloys, aluminum or aluminum alloys.

The systems of binding agents (A), components (B), as well as suitable solvents for the formulation of anticorrosive formulations are known to the specialist. Depending on the desired layer properties, it makes an appropriate selection. The surface coating can be carried out by means of usual techniques, commonly used by the specialist, preferably by spraying or spreading.

Depending on the type of metal surface, or metal body, two different preferred embodiments of the process according to the invention come into consideration.

Atmospheric corrosion protection

In the case of the invention, it is the process for the application of anticorrosive layers in protection against atmospheric corrosion. In the case of metal surfaces, which can be protected by means of the process for protecting atmospheric corrosion, any surface can be treated in principle. However, it is preferably the surfaces of metal buildings or metal constructions, or the necessary components for this purpose. Metal constructions, or buildings, are usually joined from construction steel, such as steel beams, steel tubes or steel sheets, by riveting, welding or screwing, to give the corresponding constructions. In this case, the surfaces may be in contact with atmospheric air during consumption, but they may also be surfaces that are in contact with water, earth or other corrosive means during consumption. In the case of metal surfaces that must be protected against corrosion by means of the process according to the invention, in principle any surface can be treated. However, it is preferably the surfaces of metal buildings or metal constructions, or the necessary components for this purpose. Metal constructions, or buildings, are usually joined from construction steel, such as steel beams, steel tubes or steel sheets, by riveting, welding or screwing, to give the corresponding constructions. In an embodiment of the invention, in the case of coated objects, it can be still metal constructions, such as buildings, bridges, electric poles, tanks, containers, buildings, pipelines, thermal power plants, chemical installations, ships, cranes, palisades, sheet piles, armor, tubes, tanks, tube fittings, flanges, couplings, ships, roofs and construction steel. In this embodiment, anti-corrosion coatings are extended or sprayed, usually in place. In this case it can be both a first protection or a maintenance.

Especially it concerns the surfaces of iron, steel, zinc, zinc alloys, aluminum or aluminum alloys. Steel may contain the usual alloy components, known to the specialist.

Examples of suitable alloy components for Zn or aluminum alloys are mentioned above. Zn or aluminum coatings can be applied on steel, by way of example, by means of melt immersion procedures, for example fire galvanized, or by sherardization. As long as the construction element is immobile, or the geometry of the construction element does not allow it, corresponding layers can also be applied by means of thermal injection (galvanized by injection, aluminized by injection).

In the case of atmospheric corrosion protection, anticorrosive coatings are usually extended or sprayed on site. Drying and hardening of such anticorrosive coatings is generally carried out under atmospheric conditions, that is, at approximately room temperature, as well as in the presence of air, or ambient oxygen, and usual air humidity. Depending on the degree of protection required, surface corrosion protection by means of anticorrosive paints is also called light, medium or severe corrosion protection.

Particularly preferably, the process for atmospheric corrosion protection can be used for those metal surfaces that are exposed to a corrosion load of corrosive categories C2 (according to DIN EN ISO 12944) or higher, preferably corrosive categories C3 or higher, and particularly preferably categories of corrosion C4 or higher.

In this case, the corrosivity categories according to DIN EN ISO 12944 are defined by the loss of mass referred to surface, or the decrease in thickness of non-alloy steel, or in the case of zinc, whose surfaces are exposed to a certain corrosive load for 1 year:

C2 (low corrosive): non-alloy steel: mass loss> 10 - 200 g / m2

  thickness decrease> 1.3 - 25 µm

zinc: mass loss> 0.7 - 5 g / m2

thickness decrease> 0.1 - 0.7 µm

C3 (moderately corrosive): non-alloy steel: mass loss> 200 - 400 g / m2

  thickness decrease> 25 -50 µm

zinc: mass loss> 5 - 15 g / m2

thickness decrease> 0.7 - 2.1 µm

C4 (strongly corrosive): non-alloy steel: mass loss> 400 - 650 g / m2

  thickness decrease> 50 -80 µm

zinc: mass loss> 15 - 30 g / m2

thickness decrease> 2.1 - 4.2 µm

C5-I / M (very strong): non-alloy steel: mass loss> 650 - 1500 g / m2

thickness decrease> 80 - 200 µm

zinc: mass loss> 30 - 60 g / m2

thickness decrease> 4.2 - 8.4 µm

The preparations according to the invention are used especially preferably in anticorrosive agents that are applied in corrosive categories C2 (according to DIN EN ISO 12944) or higher, preferably in corrosive categories C3 or higher, and especially preferably in categories of corrosivity C4 or higher.

In the case of the present process, it is preferably a chromium-free (VI) process, especially preferably a chromium-free process. The concept "free of chromium (VI)", or "free of chromium", in the sense of this invention, means that the preparation itself does not contain chromium (VI) compounds, or does not contain compounds of any kind. chromium, and that a corrosion inhibitor pretreatment of the metal surface with chromium (VI) compounds, or chromium compounds, is also not carried out. Naturally, this does not exclude that traces of chromium can be found in the layer - accidental itself. In this case, it can be an example of chromium traces, which come off the steel during the coating of a chromed steel.

For the execution of the process according to the invention for atmospheric corrosion protection, according to the invention, a preparation comprising at least one hardenable binder system under atmospheric conditions (A), at least one component (B), selected from the group of finely divided fillers, pigments or dyes, at least one copolymer (C), as well as at least one solvent (D).

Binder Agent System (A)

In the case of hardening agent systems (A) that can be hardened under atmospheric conditions, it is possible to use systems of common binding agents in the field of anticorrosive paints and coatings. Such binding agents, or systems of binding agents, are known in principle by the specialist. Naturally, mixtures of various systems of binding agents can also be used, assuming that undesirable effects do not occur by mixing.

The concept "binder agent system" then designates, in a known manner in principle, those formulation fractions that are responsible for film formation.

Within the scope of this invention, the concept "atmospheric corrosion protection" means that the anticorrosive coating has a layer thickness after drying of at least 40 µm, preferably at least 50 µm, especially preferably at least 60 µm, and so very especially preferably at least 80 µm, and a layer thickness up to 2 mm, preferably less than 1.5 mm, especially preferably less than 1 mm, very especially preferably less than 800 µm, and especially less than 500 µm, the coating mass hardening after application on the surface under usual environmental conditions, that is, approximately at room temperature or at room temperature, in the presence of air, as well as usual air humidity without the use of additional devices or installations. Typical hardening temperatures, depending on the environment, amount to more than 0 to 40 ° C, preferably 5 to 35 ° C, especially preferably 10 to 30 ° C, and most particularly preferably 15 to 25 ° C, in the presence of air and normal ambient humidity. The relative humidity of the air may be arbitrary, preferably between 10 and 80%, and especially preferably between 30 and 70%. It is obvious to the specialist that the time to complete hardening of the same binder agent system, according to dominant environmental conditions, may be different.

Depending on the type of binder agent system used, hardening can be developed according to various mechanisms. As an example, it can be a purely physical hardening, caused by the vaporization of the solvent used. Furthermore, it can be an oxidation hardening by reacting the binder agent system with the oxygen in the air. Finally, it can also be a chemical crosslink (reticulate reagent). Reactive binding agent systems comprise crosslinkable components. The crosslinkable components can be of low molecular weight, oligomers or polymers. In this case, it may be preferably one-component systems, or also two-component systems. Reactive crosslinking systems also comprise systems of binding agents that are hardened by moisture, in which the ambient humidity acts as a hardening component. Naturally, a binder agent system can also be hardened by a combination of different hardening processes. In the case of two component systems, the binder component and the hardener component are mixed before using the formulation in a manner known in principle.

For the execution of the invention, water-soluble or soluble organic binding agent systems can be used. Preferably these are aqueous based binder agent systems.

Binder agent systems for anticorrosive coatings, especially water-based anticorrosive systems, are known in principle by the specialist. By way of example, it may be epoxy resins, polyacrylates, styrene-acrylate polymers, polyesters, alkyd resins, polyurethanes of styrene-butadiene polymers.

The amount of binder (A) in the formulation amounts to 15 to 70% by weight, based on the total amount of components of the formulation, including the solvent. This is determined by the specialist according to desired coating properties. The amount preferably amounts to 20 to 60% by weight, and especially preferably 25 to 50% by weight.

Preferred binding agent systems for the implementation of the invention are described below.

Polyacrylates, or styrene-acrylate copolymers (A1)

In a preferred embodiment of the invention, in the case of the binder agent system it is an aqueous, or predominantly aqueous, dispersion of polyacrylates, or styrene-acrylate copolymers (A1).

Aqueous polyacrylate dispersions, or styrene-acrylate copolymers (A1), for obtaining anticorrosive paints are known by the specialist in principle. In the case of aqueous dispersions of polyacrylates (A1), it is possible to treat both primary and secondary dispersions. Appropriate polyacrylates contain as main monomers at least one (meth) alkyl acrylate, such as, for example, methyl (meth) acrylate, (meth) ethyl acrylate, butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate. These may preferably present vinyl aromatic compounds, especially styrene, as additional major monomers. The amount of main monomers together amounts, as a rule, to at least 60% by weight, preferably at least 80% by weight. In addition to the said (meth) alkyl acrylates, styrene-acrylate copolymers generally comprise at least 30% by weight, preferably at least 40% by weight, and especially preferably about 50% by weight. of styrene. The polyacrylates, or copolymers of styrene-acrylate (A1) may also have other additional comonomers, especially those with functional groups, such as hydroxy, carboxy or carboxamide groups. Examples include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, (meth) acrylamide or (meth) hydroxyalkyl acrylates. In the case of additional comonomers it is preferably acidic comonomers. In addition, optionally crosslinking monomers may also be present in reduced amounts, usually less than 4% by weight, preferably less than 2% by weight. Examples comprise (meth) butanediol acrylate, hexanediol di (meth) acrylate, or allyl acrylate.

Polyacrylates (A1) can be obtained in a manner known in principle by means of emulsion polymerization. Other details on such polymers, as well as their preparation, are disclosed, by way of example, in EP-A 157 133, WO 99/46337, or in "Paints and Coatings, 2.5. Acrylic Coatings" in Ullmann's Encyclopedia of Technical Chemistry, 6th edition 2000, Electronic Release. Among the possible polyacrylates in principle (A1), the specialist makes an appropriate selection according to the desired layer properties.

For the execution of the process, styrene-acrylate copolymers are especially suitable, comprising as main monomers at least one elastomeric acrylate, such as for example n-butyl (meth) acrylate, n-hexyl (meth) acrylate, n-acrylate -octyl or (meth) 2-ethylhexyl acrylate in admixture with styrene, as well as by way of secondary monomer at least one acidic monomer, such as (meth) acrylic acid. For use as a binding agent for the formulation, the acid groups can be completely or partially neutralized with appropriate bases, such as ammonia.

The polyacrylates used will generally have a glass transition temperature Tg in the range of 0 to 60 ° C, preferably in the range of 5 to 40 ° C (measured according to the DSC method according to DIN EN ISO 11357). The glass transition temperature can be chosen by the specialist in a manner known in principle by the selection and quantitative proportion of hard and soft monomers.

For the execution of the invention, polyacrylates (A1) with an average particle size of 50 nm to 400 nm can also be used, especially preferably 80 nm to 250 nm (measured with Malvern® Autosizer 2 C).

Acrylate dispersions, or styrene-acrylate suitable for obtaining anticorrosive paints, are commercially available, for example as Acronal® S 760 or Acronal® LR 8977 (signature BASF Aktiengesellschaft) or Acronal® Optive 410 (signature BASF Corporation) .

Styrene-Alkane Polymers (A2)

In a second preferred embodiment of the invention, in the case of the binder agent system, it is an aqueous, or predominantly aqueous, dispersion of styrene-alkadiene polymers (A2).

Aqueous dispersions of styrene-alkadiene polymers (A2) for obtaining anticorrosive paints are known in principle by the specialist, and are described, by way of example, in EP-A 47380. It may preferably be primary dispersions, but also of secondary dispersions.

Appropriate polymers (A2) comprise as main styrene monomer, as well as at least one conjugated aliphatic diene (alkadiene). In the case of alkanes, it is possible, for example, to treat butadiene, isoprene, 1,3-pentadiene or dimethylbutadiene. Styrene can also be substituted with alkyl groups. Examples comprise α-methylstyrene or 4-methylstyrene. In the case of the main monomers, it is preferably styrene and butadiene. As a general rule, the polymers contain at least 20% by weight of styrene and 20% by weight of alkanes, the amount of main monomers rising together, as a rule, at least 60% by weight, preferably at least one 80% by weight. Quantitative data refer respectively to the sum of all monomers. They may also have other comonomers. In this case, carboxylic acids and / or unsaturated dicarboxylic acids, such as (meth) acrylic acid, maleic acid or itaconic acid, must be mentioned on the one hand. In addition, it can be treated with nitriles of carboxylic acid with ethylenic unsaturation, such as (meth) acrylonitrile, as well as (meth) alkyl acrylates, such as (meth) methyl acrylate, (meth) n-butyl acrylate, (meth) acrylate n-hexyl, n-octyl acrylate or 2-ethylhexyl (meth) acrylate.

The polymers of styrene-alkane (A2) can be obtained in a known manner in principle by means of emulsion polymerization. Other details on styrene-butadiene polymers for coating substances, as well as their preparation, are disclosed, by way of example, in "Paints and Coatings, 2.4.8. Polystyrene and Styrene Copolymers" in Ullmann's Encyclopedia of Technical Chemistry, 6th edition 2000, Electronic Release.

For the execution of the invention, styrene-butadiene polymers are especially suitable, comprising as secondary monomer one or more acidic monomers, such as (meth) acrylic acid, preferably in an amount of 0.5 to 5% in weight. For use as a binding agent for the formulation, the acid groups can preferably be completely or partially neutralized with appropriate bases, such as ammonia.

The styrene-butadiene (A2) polymers used will generally have a glass transition temperature Tg in the range of 0 to 60 ° C, preferably in the range of 5 to 40 ° C. The glass transition temperature can be chosen by the specialist in a manner known in principle by the selection and quantitative proportion of hard and soft monomers.

For the execution of the invention, styrene-butadiene (A2) polymers with an average particle size of 50 nm to 400 nm may be used, especially preferably 80 nm to 250 nm (measured as above).

Polyurethanes (A3)

In a third preferred embodiment of the invention, in the case of the binder agent system it is an aqueous, or predominantly aqueous, dispersion of polyurethanes (A3).

Aqueous dispersions of polyurethanes (A3) for obtaining anticorrosive paints are known in principle by the specialist. Details about polyurethanes for coating substances are disclosed, as well as their obtaining, by way of example, in "Paints and Coatings, 2.9 Polyurethane Coatings" in Ullmann's Encyclopedia of Technical Chemistry, 6th edition 2000, Electronic Release. In the case of aqueous dispersions of polyurethanes (A3), it is possible to treat both primary and secondary dispersions.

Polyurethanes for aqueous dispersions can be synthesized in a manner known in principle from usual diisocyanates, as well as diols. With respect to good film formation and elasticity, diols with an average molecular weight in number Mn of about 500 to 5000 g / mol, preferably about 1000 to 3000 g / mol, are especially considered. To this end, both polyether diols and polyester polyols can be used. The amount of such diols with the highest molecular weight usually amounts to 10 to 100 mol% with respect to the sum of all diols. The desired hardness and elasticity of the film can be controlled using, in addition to the aforementioned diol, low molecular weight diols, with an average molecular weight in Mn number of approximately 60 to 500 g / mol.

For the synthesis of polyurethanes for aqueous dispersions, monomers comprising at least one isocyanate group or a reactive group against isocyanate groups are used, as well as, additionally, at least one hydrophilic group. In this case it can be non-ionic groups, such as polyoxyethylene groups, acid groups, such as COOH, sulfonate or phosphonate groups, or basic groups, such as amino groups. Preferably it is acid groups. For use as a binding agent for the formulation, the acid groups can be neutralized with appropriate bases, preferably completely or partially. Ammonia or amines are preferred for this purpose. Other details on such polyurethane dispersions, as well as their preparation, are described in detail in WO 2005/005565, page 4, line 13 to line 14. Other examples of suitable polyurethanes are disclosed in US 5 707 941 or in WO 2004/101638, especially page 2, line 31 to page 14, line 11.

It can be modified polyurethanes. By way of example, it can be alkyd urethane resins that are hardened by oxidation. In order to obtain it, partially, by way of example, triglycerides of unsaturated fatty acids can be hydrolyzed. The OH group produced can react with the isocyanate groups to obtain polyurethane.

Preferably, polyurethanes (A3) with an average particle size of not more than 1000 nm, preferably less than 500, especially preferably less than 200 nm, and especially 20 to 200 nm, may be used for the execution of the invention. .

Alkyd Resins (A4)

In a fourth preferred embodiment of the invention, in the case of the binder agent system it is an aqueous, or predominantly aqueous, dispersion of alkyd resins (A4).

In principle, aqueous dispersions of alkyd resins (A4) for obtaining anticorrosive paints are known to the specialist. In the case of alkyd resins (A4) these are polycondensation resins that are hardened by oxidation, consisting of polyols and polyvalent carboxylic acids, in which at least one OH group of the polyol is esterified with fatty oils and / or natural fatty acids and / or synthetic, mono- or polyunsaturated, having to be at least one of the polyols used trifunctional, or of higher functionality.

Examples of preferred polyvalent alcohols include glycerin, pentaerythrite, trimethylolethane, trimethylolpropane, different diols, such as ethane / propanediol, diethylene glycol, neopentyl glycol.

Preferred polyvalent carboxylic acids are (phthalic acid anhydride (PSA), isophthalic acid, terephthalic acid, trimellitic acid anhydride, adipic acid, acelaic acid, sebacic acid, is especially preferred (anhydride of) phthalic acid.

As an oil component, or fatty acid, desiccant oils, such as flaxseed oil, oiticic oil or wood oil, semi-drying oils, such as soybean oil, sunflower oil, saflor oil, are considered, for example. castor oil or talol, non-desiccant oils, such as castor oil, coconut oil or peanut oil, or free fatty acids from the above oils.

The molecular weight Mn of typical alkyd resins is between 1500 and 20,000 g / mol, preferably between 3500 and 6000 g / mol. The acid number preferably amounts to 2 to 30 mg of KOH / g, in the case of water-dilutable resins also 35-65 mg of KOH / g. The OH number is generally up to 300, preferably up to 100 mg of KOH / g.

The concept "alkyd resin" will also comprise modified alkyd resins, such as alkyd resins modified with styrene, alkyd resins of urethane, urethane oils, or alkyd resins modified with epoxy resin. Such modified alkyd resins are known to the specialist.

Other particularities on alkyd resins (A4) for coating substances, as well as their obtaining, are disclosed, by way of example, in "Paints and Coatings, 2.6. Alkyd Coatings" in Ullmann's Encyclopedia of Technical Chemistry, 6th edition 2000, Electronic Release, as well as in "Lackformulierung und Lackrezeptur", ed. Ulrich Zorll, pages 188 et seq., Curt R. Vinzentz Verl., Hannover, 2003.

The alkyd resins used (A4) will generally have a glass transition temperature Tg in the range of 0 to 60 ° C, preferably 5 to 40 ° C.

Filler / pigment / dye (B)

The preparation used according to the invention further comprises at least one component (B) selected from the group of finely divided fillers, pigments or dyes.

In the case of finely divided cargo, it is generally an inorganic charge. Naturally, fillers and / or pigments may comprise an additional organic coating, by way of example for hydrophobizing or hydrophilizing.

The charge will not exceed an average particle size of 10 µm. The average particle size preferably amounts to 10 nm to 8 µm, especially preferably 100 nm to 5 µm, and by way of example 2 to 4 µm. In the case of spherical or approximately spherical particles, this data refers to the diameter, in the case of irregularly shaped particles, as for example in the case of acicular particles, it refers to the longest axis. With particle size the primary particle size is indicated. Naturally, it is known to the specialist that finely divided charges frequently agglomerate to give larger particles, which must be dispersed intensively for use. The particle size is selected by the specialist according to the desired layer properties.

In the case of pigments, it can be treated in particular anti-corrosive pigments. It can be anti-corrosive pigments both active and passive.

Examples of active anti-corrosive pigments include, in particular, phosphates, pigments containing phosphates or modified phosphates, such as zinc phosphate-based pigments, zinc-aluminum orthophosphate, zinc-molybdenum orthophosphate, zinc-aluminum-molybdenum orthophosphate, hydrogen phosphate calcium, zinc-calcium-aluminum orthophosphate-silicate, zinc-aluminum polyphosphate, strontium-aluminum polyphosphate, zinc-calcium-aluminum-strontium orthophosphate-silicate, calcium-aluminum polyphosphate-silicate. Other examples include combinations of inorganic phosphates with organic corrosion inhibitors with electrochemical activity, such as zinc phosphate modified with salts of Zn or Ca of 5-nitroisophthalic acid. In addition, iron phosphide, zinc hydroxyphosphide, borosilicate pigments, such as barium metaborate or zinc borophosphate, molybdates, such as zinc molybdate, sodium-zinc molybdate or calcium molybdate, pigments with ion exchange properties can also be used. , such as amorphous SiO2 modified with calcium ions, or correspondingly modified silicates, metal oxides, such as ZnO, or also metal powder, such as zinc dust. Naturally, organic anticorrosive pigments, such as Zn or Ca salts of 5-nitroisophthalic acid, can also be used.

Passive anticorrosive pigments prolong diffusion pathways for corrosive action components, and thus increase corrosion stability. Examples include, above all, platelet-shaped or lamella-shaped pigments, such as mica, hematite, layered silicates, linear polysilicates, such as volastonite, talc, or metal platelets, such as aluminum or iron platelets.

Other particularities on anticorrosive pigments are found, for example, in "Pigments, 4.2 Anticorrosive Pigments" in Ullmann's Encyclopedia of Technical Chemistry, 6th edition 2000, Electronic Release.

In the case of pigments it can also be pigments of color and / or effect.

Effect pigments should be understood as all pigments that show a platelet-shaped structure and grant special decorative color effects to a surface coating. Effect pigments are known to the specialist. Examples include pure metallic pigments, such as aluminum, iron or copper pigments, interference pigments, such as for example titanium dioxide coated mica, iron oxide coated mica, mixed oxide coated mica (for example with mixed dioxide titanium and Fe2O3), aluminum coated with metal oxide, or liquid crystal pigments.

In the case of color pigments it is especially organic or inorganic absorption pigments that can be used in the enamels industry. Examples of organic absorption pigments are azo pigments, phthalocyanine pigments, quinacridone pigments and pyrrolopyrrole. Examples of inorganic absorption pigments are iron oxide, titanium dioxide and soot pigments.

Examples of azo dyes, azine, anthraquinone, acridine, cyanine, oxazine, polymethine, thiazine, triarylmethane dyes are examples. These dyes may find application as basic or cationic dyes, strippers, direct dyes, dispersion, development, tub, metal complex, reagent, acid, sulfur, copulate or substantive dyes.

With loads, the properties of the coating can be influenced, such as hardness, rheology, or the orientation of the effect pigments. Loads are often ineffective from a color point of view; that is, they have a reduced absorption of their own, and the refractive index is similar to the refractive index of the coating medium. Examples of charges include talc, calcium carbonate, kaolin, barium sulfate, magnesium silicate, aluminum silicate, crystalline silicon dioxide, amorphous silicic acid, aluminum oxide, hollow microbeads or microbeads, for example glass, ceramics, or polymers with exemplary sizes of 0.1-10 µm. In addition, any organic inert solid particle can be used as a filler, such as condensation products of urea-formaldehyde, micronized polyolefin wax, or micronized amide wax. The inert loads can also be used in admixture in each case. However, only one load is used respectively.

The components (B) are used in an amount of 1 to 70% by weight. The exact amount is determined by the specialist according to the desired layer properties. The amount preferably amounts to 5 to 60% by weight, and especially preferably 10 to 50% by weight.

In the case of the use of pigments and / or fillers, volumetric pigment concentrations (PVK) of 15 to 40% by volume, preferably 20 to 40% by volume, have been successful, and especially so preferably 20 to 35% by volume, without the invention being limited thereto.

The type and quantity of components (B) is determined by the specialist according to the end of use of the layer. In a particularly preferred embodiment of the invention, chromed components (B) are not used. Naturally, mixtures of various components (B) can also be used.

Preparations intended for priming are usually pigmented to a greater extent than preparations intended only for intermediate or covering coating.

Preparations intended for priming usually comprise at least one active anti-corrosive pigment, preparations intended for intermediate coatings comprise at least one passive anti-corrosive pigment, and preparations for covering coatings comprise at least one color pigment and / or a dye.

In a particularly preferred embodiment, the preparations intended for priming comprise at least one active anticorrosive pigment, at least one filler, as well as, preferably, at least one color pigment.

Copolymer (C)

To obtain the preparation for atmospheric corrosion protection used according to the invention, a single copolymer (C) or several different copolymers (C) can be used. The specialist makes an appropriate selection among the copolymers (C) possible in principle according to the desired anticorrosive layer properties. It is obvious to the specialist that not all types of copolymers (C) are conveniently suitable to the same extent for all types of binder agent systems, solvents or surfaces.

For atmospheric corrosion protection, copolymers (C) with COOH and / or sulfonic acid groups may be used. Copolymers comprising itaconic acid as monomers (C2) are very particularly preferred.

The copolymers (C) used according to the invention are used in an amount of 0.1 to 40% by weight, preferably 0.2 to 20% by weight, and especially preferably 0.5 to 10 % by weight, referred respectively to the total amount of components of the formulation.

Solvents (D)

The preparation for atmospheric corrosion protection comprises as component (D) an appropriate solvent. Suitable solvents are those that are suitable for dissolving, dispersing, suspending or emulsifying the components used according to the invention, to enable a uniform application of the preparation on the surface. In this case it can be organic solvents or water. Naturally, it can also be mixtures of various solvents.

Examples of organic solvents include hydrocarbons, such as toluene, xylene, as well as especially mixtures of hydrocarbons of certain boiling ranges, as obtained in the refining of crude oil, ethers, such as THF or polyether, such as polyethylene glycol, etheric alcohols, such as butyl glycol. , ether glycol acetates, such as butyl glycol acetate, ketones, such as acetone, alcohols, such as methanol, ethanol or propanol.

In the case of the solvent it is preferably water, or a predominantly aqueous solvent mixture. It should be understood as those mixtures containing at least 75% by weight, preferably at least 85% by weight, especially preferably at least 90% by weight, and very particularly preferably at least 95% by weight. water weight

In the case of additional components of predominantly aqueous solvent mixtures, these may be water miscible solvents. Examples especially comprise typical co-solvent agents, such as nbutanol, butyl glycol, butyldiglycol, tert-butyl acetate, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or N-cyclohexyl-2-pyrrolidone. However, in the case of other components it can be solvents that are not miscible with water. Such solvents are often used as auxiliary film-forming agents. Examples include butyl glycol acetate, butyl glycol diacetate or 2,2,4-trimethyl-1,3-pentane-1-diol (Texanol®) 1-isobutyrate.

The amount of solvent or solvent mixture (D) amounts to 5 to 83.9% by weight, based on the sum of all the components of the formulation. This is determined by the specialist according to the desired paint formulation properties. The amount preferably amounts to 10 to 74.8% by weight, especially preferably 20 to 64.5% by weight, and, for example, 30 to 50% by weight.

Other components (E)

Apart from components (A) to (D), the preparation for atmospheric corrosion protection used according to the invention may still contain one or more auxiliary and / or additive products (E). Such auxiliary substances and / or additives serve for the fine control of layer properties. In the general case, its quantity does not exceed 20% by weight with respect to the sum of all components, with the exception of solvents, preferably it does not exceed 10%.

Examples of additives suitable for application in atmospheric corrosion protection include rheological auxiliary agents, UV filters, sunscreen agents, radical scavengers, catalysts for thermal crosslinking, sliding additives, polymerization inhibitors, antifoams, emulsifiers, degassing agents, wetting agents and dispersants , bonding agents, eluting agents, film-forming auxiliary agents, rheological additives (thickeners), flame retardant agents, thickeners, film-forming inhibitors, other corrosion or wax inhibitors, and matting agents. Such additives are disclosed, by way of example, in "Lackadditive", editor Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998, or DE-A 199 14 896, paragraph 13, line 56, to paragraph 15 , line 54.

The preparation for the implementation of the procedure can be obtained by intensive mixing of all the components of the preparation. For the specialist with known appropriate mixing or dispersion aggregates.

In a preferred embodiment of the invention, a dispersion can first be obtained from the binder system (A), the copolymer (C), as well as at least a part of the solvent (D). As long as in the case of the binding agent (A) it is a primary dispersion, naturally the binding agent is pre-dispersed in itself. As long as the binder is present as a solid product, first a solution is obtained, or a secondary dispersion. The copolymer (C) is used dissolved, emulsified or dispersed in a solvent equally preferably. For this purpose, the solutions, or emulsions of copolymers (C), which are produced in obtaining copolymers (C), are advantageously employed, without the copolymers being previously isolated.

The components (B), as well as, where appropriate, other components (E), can be dissolved, or dispersed in the previous dispersion below.

Execution of the procedure for atmospheric corrosion protection

In the case of anticorrosive layers, all types of anticorrosive coatings can be treated, such as primers (I), intermediate coatings (II) and cover coatings (III). Naturally, it can also be anti-corrosive coatings, which combine the properties of at least two of these layers, or of the three layers, and thus contribute to a simplified layer structure. It can also be a finished coating. The specialist understands by this a layer that can be applied on freshly irradiated steel, to guarantee anticorrosive protection even during the finishing of steel components, that is, by way of example during the welding of parts.

The process according to the invention can be used for first protection, or also for maintenance.

In the general case it is recommended to prepare the metal surface for the implementation of the process according to the invention in a process step (0), also if this is not absolutely forced in any case. The specialist understands by surface preparation for the implementation of anticorrosive measures the purification of the surface of all impurities, as well as the adjustment of a surface roughness adjusted to the measure of corrosion protection. Examples of purification procedures include cleaning with water or solvents, pickling with appropriate formulations, or high pressure purification. Examples of subsequent measures include grinding, and especially surface blasting, by way of example sand blasting, as well as, also, etching by blowtorch. In this case, all adhesive layers can be unloaded until they reach the pure metal. However, it is also possible to discharge only low adhesive layers under less intensive methods, while intact layers remain on the surface. A possible technique for this purpose is scanning irradiation.

For the execution of the procedure, at least one anticorrosive layer with a thickness of at least 15 µm is applied on the metal surface, using the described preparation, crosslinkable under atmospheric conditions.

In this case, the anticorrosive layer can be applied immediately on the bare metal surface, or on a surface already previously coated with an anticorrosive layer.

In the case of at least one anticorrosive layer it is a primer layer (I), which is applied directly on the bare metal, or on a metal surface that has a finished coating. The finished coating optionally present can also be obtained with the formulation according to the invention,

or also by means of another formulation.

The usual techniques known by the specialist can be used for the application. Preferably the preparation is spread or sprayed.

After application on the surface, the applied coating hardens in the process step (2) under atmospheric conditions. This can be done by gradually evaporating the solvent in the simplest of cases. Depending on the nature of the binder used, other crosslinking processes can be developed. Details were previously presented for this purpose.

Depending on the thickness of the anticorrosive layer desired, the total layer can be applied in a single working step, or several layers of the same type can be applied and hardened, respectively, to achieve the total layer thickness of the anticorrosive layer.

On the primer (I) other anticorrosive layers can be applied. The type and number of additional layers is determined by the specialist. In particular, the primer (I) can be provided with an intermediate layer (II) and a covering layer (III) in additional work steps. For this purpose, in principle any enamel system can be used, assuming that in combination with the primer (I) there are no undesirable effects. The adhesion of subsequent layers on the primer is improved by the copolymer (C) used according to the invention. For primer (I), for the intermediate layer (II), as well as for the covering layer, preparations according to the invention can be used advantageously.

In another preferred method of executing the process, an integrated primer (Ia) is applied first, which can be varnished with a covering varnish (III). Therefore, an integrated primer combines the properties of the primer (I) and the intermediate layer (III).

In another preferred embodiment of the invention, only a single anticorrosive layer (Ib) is applied, which does not need to be varnished. Therefore, such an isolated anticorrosive layer combines the properties of the three layers.

The total thickness of such anticorrosive paints is determined by the specialist according to the desired anticorrosive layer properties. As a general rule, this amounts to at least 40 µm, preferably at least 50 µm, especially preferably at least 60 µm, and most particularly preferably at least 80 µm, especially at least 100 µm, especially at least 125 µm, often at least 150 µm, and even at least 175 µm, or at least 200 µm. The upper limit of total layer thickness, that is, the thickness of all the anticorrosive layers applied together, amounts to 2 mm, preferably less than 1.5 mm, especially preferably less than 1 mm, very particularly preferably less 800 µm, and especially less than 500 µm.

The following examples will explain the invention in more detail.

Part I: obtaining polymer corrosion inhibitors

Polymer 1

Copolymer consisting of 35 mol% acrylonitrile, 15 mol% itaconic acid, and 50 mol% styrene

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 77 g of itaconic acid in 314.8 g of tetrahydrofuran were heated to 65 ° C. In the 5 h interval a feed 1 consisting of 74.2 g of acrylonitrile and 207.9 g of styrene was added, and in the 6 h interval a feed 2 consisting of 21.6 g of 2,2'-azobis (2,4-dimethylvaleronitrile) (trade name WAKO® V-65) in 120 g of tetrahydrofuran. The reaction mixture was stirred an additional 2 h at 65 ° C. Then 3.6 g of WAKO V-65 in 36 g of tetrahydrofuran were added in the range of 1 h, and an additional 4 h was stirred. The polymer 1 obtained is a clear, yellow solution, with a solid product content of 48.5% and a K value of 20.9.

1st polymer

Polymer 1a (with a solid product content of 23.8%) was obtained by mixing 30 g of polymer 1, 22.5 g of butyl glycol, 15 g of water and 2.0 g of dimethylethanolamine.

1b polymer

Polymer 1b (with a solid product content of 30.4%) was obtained by mixing 30 g of polymer 1, 15 g of butyl glycol, 12 g of water and 4.0 g of dimethylethanolamine.

Polymer 2

Copolymer consisting of 50 mol% acrylonitrile, 20 mol% itaconic acid, and 30 mol% styrene

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 111.8 g of itaconic acid in 314.8 g of tetrahydrofuran were heated to 65 ° C. In the 5 h interval, a feed 1 consisting of 114 g of acrylonitrile and 134.2 g of styrene was added, and in the 6 h interval a feed 2 consisting of 21.6 g of WAKO® V-65 in 120 g of tetrahydrofuran. The reaction mixture was stirred an additional 2 h at 65 ° C. Then 3.6 g of WAKO V-65 in 36 g of tetrahydrofuran were added in the range of 1 h, and an additional 4 h was stirred. The polymer 2 obtained was diluted with 250 g of tetrahydrofuran, and provided a clear, yellow solution, with a solid product content of 50.7% and a K value of 20.4.

2nd polymer

Polymer 2a (with a solid product content of 26.8%) was obtained by mixing 30 g of polymer 2, 15 g of butyl glycol, 20 g of water and 3.0 g of dimethylethanolamine.

2b polymer

Polymer 2b (with a solid product content of 29.9%) was obtained by mixing 30 g of polymer 2, 15 g of butyl glycol, 20 g of water and 6.0 g of dimethylethanolamine.

Polymer 3

Copolymer consisting of 20 mol% acrylonitrile, 40 mol% itaconic acid, and 40 mol% styrene

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 179.6 g of itaconic acid in 314.8 g of tetrahydrofuran were heated to 65 ° C. In the 5-hour interval a feed 1 consisting of 36.6 g of acrylonitrile and 143.8 g of styrene was added, and in the 6 h interval a feed 2 constituted of 21.6 g of WAKO® V-65 in 120 g of tetrahydrofuran. The reaction mixture was stirred an additional 2 h at 65 ° C. Then 3.6 g of WAKO V-65 in 36 g of tetrahydrofuran were added in the range of 1 h, and an additional 4 h was stirred. The polymer 3 obtained was diluted with 250 g of tetrahydrofuran, and provides a clear, yellow solution, with a solid product content of 49.5% and a K value of 18.7.

Polymer 3a (with a solid product content of 30.2%) was obtained by mixing 30 g of polymer 3, 15 g of butyl glycol, 15 g of water and 4.7 g of dimethylethanolamine.

Polymer 4

Copolymer consisting of 20 mol% acrylonitrile, 40 mol% itaconic acid, and 40 mol% styrene

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 280.2 g of itaconic acid in 380.8 g of 2-butoxyethanol were heated to 90 ° C. In the 5 h interval, a feed 1 consisting of 57.1 g of acrylonitrile and 224.3 g of styrene was added, and in the 6 h interval a feed 2 consisting of 33.7 g of tert-butyl peroctoate in 303.4 of 2-butyloxy-ethanol. The reaction mixture was stirred one more hour at 90 ° C. The temperature of the reaction mixture was then increased to 95 ° C, and in the range of 1 h 5.6 g of sodium peroxodisulfate in 77.5 g of VE water (completely desalinated) was added, and stirred an additional hour at 95 ° C. . The step was repeated three more times with analogous conditions. The polymer obtained provides a dark yellow, cloudy solution with a solid product content of 38.3%.

4th polymer

Polymer 4a (with a solid product content of 30.0%) was obtained by mixing 75 g of polymer 4, 41.6 g of VE water and 8.9 g of dimethylethanolamine.

4b polymer

Polymer 4b (with a solid product content of 30.0%) was obtained by mixing 75 g of polymer 4, 55.6 g of VE water and 14.9 g of triethanolamine.

4c polymer

Polymer 4c (with a solid product content of 30.0%) was obtained by mixing 75 g of polymer 4, 17.1 g of VE water and 14.0 g of 25% ammonia solution.

Polymer 5

Copolymer consisting of 21.1 mol% acrylonitrile, 36.9 mol% itaconic acid, and 42.0 mol% styrene

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 246.4 g of itaconic acid in 380.8 g of 2-butoxyethanol were heated at 90 ° C. In the 5 h interval, a feed 1 consisting of 57.1 g of acrylonitrile and 224.3 g of styrene was added, and in the 6 h interval a feed 2 consisting of 33.7 g of tert-butyl peroctoate in 303.4 of 2-butyloxy-ethanol. The reaction mixture was stirred one more hour at 90 ° C. The temperature of the reaction mixture was then increased to 95 ° C, and in the range of 1 h, 5.6 g of sodium peroxodisulfate in 77.5 g of VE water was added, and another 1 hour was stirred at 95 ° C. The step was repeated three more times with analogous conditions. The polymer obtained provides a dark yellow, cloudy solution with a solid product content of 37.0%.

5a polymer

Polymer 5a (with a solid product content of 30.0%) was obtained by mixing 68.4 g of polymer 5.33.0 g of VE water and 7.3 g of dimethylethanolamine.

Polymer 5b

Polymer 5b (with a solid product content of 30.0%) was obtained by mixing 70.0 g of polymer 5, 39.6 g of VE water, 1.5 g of itaconic acid and 8.5 g of dimethylethanolamine.

Polymer 6

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 246.4 g of itaconic acid in 380.8 g of propylene glycol monobutyl ether were heated at 90 ° C. In the 5 h interval, a feed 1 consisting of 57.1 g of acrylonitrile and 224.3 g of styrene was added, and in the 6 h interval a feed 2 consisting of 33.7 g of tert-butyl peroctoate in 303.4 propylene glycol monobutyl ether. The reaction mixture was stirred one more hour at 90 ° C. The temperature of the reaction mixture was then increased to 95 ° C, and in the range of 1 h, 5.6 g of tert-butyl peroctoate in 50.4 g of propylene glycol monobutyl ether was added, and another 1 hour was stirred at 95 ° C. . The step was repeated three more times with analogous conditions. The polymer obtained provides a dark, transparent yellow solution with a solid product content of 39.7%.

Polymer 6a Polymer 6a (with a solid product content of 30.0%) was obtained by mixing 63.7 g of polymer 6, 37.7 g of VE water and 7.3 g of dimethylethanolamine.

Polymer 6b

Polymer 6b (with a solid product content of 30.0%) was obtained by mixing 65.2 g of polymer 6, 44.4 g of VE water, 1.5 g of itaconic acid and 8.5 g of dimethylethanolamine.

Polymer 7

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 215.5 g of itaconic acid in 292.8 g of n-butanol were heated at 90 ° C, mixed with 147.7 of dimethylethanolamine. A feed 1 consisting of 43.9 g of acrylonitrile and 172.6 g of styrene was added in the 5 h interval, and in the 6 h interval a feed 2 constituted of 25.9 g of tert-butyl peroctoate in 233.4 of n-butanol. The reaction mixture was stirred one more hour at 90 ° C. Then 4.3 g of tert-butyl peroctoate in 59.6 g of n-butanol were added in the range of 1 h, and an additional 1 h was stirred at 95 ° C. The step was repeated 2 more times under analogous conditions, stirring 2 h subsequently after the last addition. The temperature in the heating bath was increased to 120 ° C.

After adding 250 g of water VE, n-butanol was removed by azeotropic distillation by introduction of water vapor. The polymer obtained provides a dark yellow, transparent solution, with a solid product content of 34.7%.

Polymer 8

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 179.6 g of itaconic acid in 209.9 g of n-butanol and 104.9 g of water were heated at 90 ° C GO. In the 5 h interval, a feed 1 consisting of 36.6 g of acrylonitrile and 143.8 g of styrene was added, and in the 6 h interval a feed 2 consisting of 21.6 g of tert-butyl peroctoate in 194.4 of n-butanol. The reaction mixture was stirred one more hour at 90 ° C. Then 3.6 g of tert-butyl peroctoate in 32.4 g of n-butanol were added in the range of 1 h, and an additional 1 h was stirred at 95 ° C. The step was repeated 2 more times under analogous conditions, stirring 2 h subsequently after the last addition. The temperature in the heating bath was increased to 105 ° C.

After adding 123.1 g of dimethylethanolamine in 500 g of VE water in the 30 minute interval, nbutanol was removed by azeotropic distillation by introduction of water vapor. The polymer obtained provides a yellow solution, almost transparent, with a solid product content of 33.5%.

Polymer 9

In a pilot stirring mechanism of 2 l, with anchor stirrer and internal thermometer, 229.0 g of itaconic acid in 311.1 g of tetrahydrofuran were heated at 65 ° C. In the 5-hour interval a feed 1 consisting of 46.7 g of acrylonitrile and 183.3 g of styrene was added, and in the 6 h interval a feed 2 constituted of 27.5 g of Wako V 65 in 247, 9 g of tetrahydrofuran. The reaction mixture was stirred one more hour at 65 ° C. Then 4.6 g of Wako V 65 in 41.3 g of tetrahydrofuran were added in the range of 1 h, and an additional 2 h was stirred at 70 ° C. The temperature in the heating bath was increased to 95 ° C. 270 g of tetrahydrofuran were distilled. The temperature in the heating bath was increased to 100 ° C and 200 g of VE water were added with dosage in the 1 hour interval, in this case 170 g of tetrahydrofuran / VE water were distilled.

After addition of 157.1 g of dimethylethanolamine in 600 g of VE water in the 60 minute interval, tetrahydrofuran was distilled by introduction of water vapor. The polymer obtained provides a yellow solution, almost transparent, with a solid product content of 31.2%.

Part II: technical application controls

For the technical application control three different anticorrosive formulations based on two commercial aqueous styrene-acrylate dispersions for paints (Acronal® Optive 410, signature BASF Corp., as well as Acronal® S 790, signature BASF AG) were used, as well as a laboratory sample of a dispersion based on n-butyl acrylate and styrene as the main monomers, which was obtained analogously to EP 1062282. The dispersions used have the following properties:

Acronal® Optive 410

Acronal® S 790 Laboratory sample

Solid product content

49-51% 49-51% Approx. 50-51%

pH

7.5-8.5 7.5-9.0 Approx. 9.5

Viscosity

500-1000 cps (Brookfield) 700-1500 mPas (in 100s-1) Approx. 200 mPas (in 100s-1)

Density

1.06 g / cm3 1.08 g / cm3 Not determined

MFFT (Minimum FilmForming-Temperature (according to ASTM D 2354, or ISO 2115))

Approx. 12ºC Approx. 20ºC Not determined

Particle size

Approx. 110 nm Approx. 135 nm Approx. 125 nm

To obtain the formulations according to the invention, 3% by weight of copolymers in each case was added to the respective styrene-acrylate dispersion (calculated as a solid copolymer with respect to the solid product fraction dispersion). For this purpose the copolymer solutions containing butyl glycol described above were used.

For comparison purposes, a sample was obtained, respectively, without the addition of a polymer corrosion inhibitor in the case of Acronal® Optive 410-based enamels, or Acronal® S 790, in the series of laboratory-based tests. as an alternative polymer inhibitor comparison.

10 Recommended formulation for anticorrosive primers

Under the use of the aqueous dispersions obtained, consisting of styrene-acrylate copolymer, with and without the addition of anticorrosive polymers, preparations were obtained according to the following prescription.

Acronal® Optive 410 based enamel

393.4 g of the respective aqueous polymer dispersion were mixed with 2.2 g of a commercial antifoam for

15 enamels (mixture of polysiloxanes and hydrophobic solid substances in polyglycol; BYK® 022, signed Byk), then a mixture consisting of 0.6 g of an anionic dispersing agent (acid phosphate of an alkoxylate of an alkoxylate of fatty alcohol; Lutensit® A-EP, signed by BASF AG), 11.0 g of concentrated ammonia and 58.6 g of water. Under stirring, a mixture consisting of 7.2 g of phenoxypropanol (film-forming auxiliary agent) and 7.2 g of benzine (boiling range 180-210 ° C, auxiliary agent) was incorporated

20 film forming).

Next, 85.0 g of a hematite pigment (Bayferrox® 130 M, Lanxess signature), 82.1 g of an anticorrosive pigment based on zinc phosphate (Heucophos® ZMP, modified zinc phosphate, Heubach signature) were added , 36.0 g of magnesium silicate (filler; talc 20 M 2, Luzenac), as well as 127.8 g of a charge based on barium sulfate and zinc sulphide (30% ZnS) (Litopone® L , signature Sachtleben). The total mixture dispersed

25 for at least 30 minutes with glass beads (Ø 3 mm). Then another 166.4 g of polymer dispersion, 1.9 g of BYK® 022, as well as 3.7 g of a 1: 1 mixture consisting of water and a commercial corrosion inhibitor (corrosion inhibitor) were added with additional stirring L 1, signature Erbslöh), and the glass beads were sieved.

To conclude, the filler was combined with a mixture consisting of 3.7 g of a 25% solution of an agent

30 commercial thickener based on urethane (Collacral® PU 85, signed by BASF AG) and 13.2 g of butyl glycol (solvent), as well as, if necessary, the pH value was readjusted to approximately 9.5 with concentrated ammonia. 1000 g of an anticorrosive primer with 61% solid product content and a volumetric pigment concentration (PVK) of 23% was obtained.

Acronal® S 790 based enamel

530.6 g of the respective aqueous polymer dispersion were mixed with 2.8 g of a commercial antifoam for enamels (combination of liquid hydrocarbons, hydrophobic silicic acid, fatty products, oxalkylated compounds and non-ionic emulsifiers; Agitan® 295, signature Münzing-Chemie), then a mixture consisting of 0.9 g of an anionic dispersing agent (sodium salt of a medium molecular weight polyacrylic acid, 35% in water; NL pigment distributor, was added by means of a Dispermat signature BASF AG), 20.8 g of concentrated ammonia and 115.7 g of water. Under stirring, a mixture of 9.2 g of phenoxypropanol (film-forming auxiliary agent) and 9.2 g of benzine (boiling range 180-210 ° C, film-forming auxiliary agent) was incorporated.

Then 74.7 g of a hematite pigment (Bayferrox® 130 M, Lanxess signature), 74.7 g of an anticorrosive pigment based on zinc phosphate (Heucophos® ZMP, modified zinc phosphate, Heubach signature) were added , 37.1 g of calcium carbonate (charge; Millicarb, Omya firm), as well as 112.2 g of a charge based on barium sulfate and zinc sulphide (30% by weight of ZnS) (lithopone® L, Sachtleben signature). The total mixture was dispersed for at least 30 minutes with glass beads (Ø 3 mm). Then 1.9 g of Agitan® 295, 3.5 g of a 1: 1 mixture consisting of water and a commercial corrosion inhibitor (commercial corrosion inhibitor L 1, signature Erbslöh), as well as 1, were added under subsequent stirring. 9 g of a kettle preservative based on chloromethyl- and methylisothiazolone + N- / O-formal (Parmetol A 26, signed Schülke & Mayr), and the glass beads were sieved.

Finally, the filler was combined with a mixture consisting of 2.2 g of a 25% solution of a commercial thickener based on urethane (Collacral® PU 75, signed by BASF AG) and 2.6 g of butyl glycol (solvent), as well as, if necessary, the pH value was readjusted to approximately 9.5 with concentrated ammonia. 1000 g of an anticorrosive primer with 57% solid product content and a volumetric pigment concentration (PVK) of 23% was obtained.

Enamel based on laboratory sample

250 g of the respective aqueous polymer dispersion (approximately 50%) were mixed with 1.14 g of a commercial antifoam for enamels (mixture of polysiloxanes and hydrophobic solid products in polyglycol; BYK® 022, signature Byk), as well as with 2.22 g of a wetting agent (Surfynol® 104, 50% in n-propanol; Air-Products signature), then a mixture consisting of 0.6 g of an anionic dispersing agent was added by means of a Dispermat ( acid phosphate of a fatty alcohol alkoxylate; Lutensit® A-EP, signed by BASF AG), 1.56 g of concentrated ammonia and 41.6 g of water. Under stirring, a mixture of film-forming auxiliary agents consisting of 4.5 g of phenoxypropanol, 4.5 g of butyl glycol and 4.5 g of benzine (boiling range 180210 ° C) was incorporated.

Then 68.0 g of a hematite pigment (Bayferrox® 130 M, Lanxess signature), 65.9 g of an anticorrosive pigment based on zinc phosphate (Heucophos® ZMP, modified zinc phosphate, Heubach signature) were added , 28.3 g of magnesium silicate (charge; talc 20 M 2, signed Luzenac), as well as 102.2 g of a charge based on barium sulfate and zinc sulphide (30% by weight of ZnS) (lithopone ® L, Sachtleben firm). The total mixture was dispersed for at least 30 minutes with glass beads (Ø 3 mm). Then 1.14 g of BYK® 022, as well as 3.24 g of a 1: 1 mixture consisting of water and a commercial corrosion inhibitor (commercial corrosion inhibitor L 1, signed Erbslöh), were added under subsequent stirring, and they separated by sieving the glass beads.

Finally, the filler was combined with a mixture consisting of 2.2 g of a 25% solution of a commercial thickener based on urethane (Collacral® PU 75, signed by BASF AG) and 2.2 g of butyl glycol (solvent), as well as, if necessary, the pH value was readjusted to approximately 9.5 with concentrated ammonia. Approximately 600 g of an anticorrosive primer with about 66% solid product content and a volumetric pigment concentration (PVK) of 35% was obtained.

Application of formulations on steel sheets, preparation for salt spray test

The primers to be analyzed were diluted with completely desalinated water to the desired viscosity, from 300 to 1000 mPas (measured with a 455N / 65 Digital Rotothinner® from Sheen Instruments), and spread over a sheet of unpolished galvanized steel (200 x 80 x 0.9 mm) with a glass scraper; in this case, the groove size is selected so that a dry layer thickness of 60-85 µm results.

After drying for six days at room temperature, as well as a one-day tempering at 50 ° C, the back of the test sheet for corrosion protection was coated with a solvent-based enamel, and in the same way the edges were glued with Tesa® -Film.

Next, the test sheet on the side coated with the primer to be analyzed was scratched to the substrate with a scratch pin.

Salt spray test / titration

A salt spray test according to DIN EN ISO 7253 was carried out with the samples, for Acronal® Optive 410-based enamels, as well as Acronal® S 790, the test time was 400 h, for base-based enamels of the laboratory sample amounted to 576 h.

In this case, the evaluation was carried out by optical comparison of the samples tested with the standard predetermined by ISO 7253.

For the assessment of corrosion behavior

Spread bubbles in the crack

Minimum or maximum elimination in mm of bubbles caused by corrosion starting at the point of artificial injury according to ISO 4628-2.

Crack adhesion removal

In contrast to the reticular cut (see below), enamel adhesion is analyzed in the direct environment of the point of artificial injury. For this purpose, immediately after the saline spray test, the coating is glued along the crack with an adhesive strip, the enamel is cut at the edges of the adhesive strip, and then the adhesive strip is removed ("Tesa®- Abriss "). The minimum or maximum distance in mm of the metallic bottom discovered by the break is measured, starting from the point of artificial injury.

Lower crack oxidation

From the point of artificial injury, rust forms below the lining. The value indicates the minimum or maximum distance, in mm, of the iron oxide formed in this case, measured from the crack; in this case, prior to sampling, the metal bottom was usually released by means of the "Tesa®-Abriss" mentioned above.

Surface corrosion

Corroded surface fraction in proportion to the total area of the test sheet in [%].

Lattice cut (according to DIN EN ISO 2409)

The adhesion of enamel on the bottom is determined by means of the reticular cutting test. For this purpose, after the saline spray test, a reticulum consisting of several sections (distance of 2 mm lines) is cut in the enamel, it is glued with an adhesive strip, and then the adhesive strip is removed. The appearance of the reticulum was assessed after removing the adhesive strip. Notes from 0 to 5 are indicated according to the following scale.

GT 0 the cutting edges are completely smooth, and none of the squares of the crosshairs have been detached.

GT 1 the coating has detached along the cutting edges, but the detached surface is not essentially greater than 15% reticular cutting surface.

GT 2 The detached reticular surface is clearly greater than 15%, but is not essentially greater than 35%.

GT 3 the coating has partially or completely detached in wide bands along the cutting edges, or some squares have been completely or partially detached.

GT 4 the affected reticular surface, however, is not greater than 65%.

GT 5 any detachment that can be classified as stronger than GT 4.

The test results are gathered in Table 1 (Acronal® Optive 410-based enamels), as well as 2 (Acronal® S 790-based enamels). In Figure 1 (Acronal® Optive 410-based enamels), as well as 2 (Acronal® S 790-based enamels), blank sample surface test sockets and enamels with polymer 3 are collected.

The data in Tables 1 and 2, as well as the figures, show that corrosion is clearly inhibited by the copolymers used according to the invention (polymers 1a, 1b, 2a, 2b and 3) compared to a sample without polymer corrosion inhibitors. . While in the case of Acronal® Optive 410-based enamels, a marked formation of bubbles in the crack is reached, accompanied by loss of adhesion and lower oxidation in the comparative sample without corrosion inhibitor, this tendency is clearly reduced, or it is not present in the examples according to the invention. An analogy can be established for Acronal® S 790-based enamels, in which the comparative sample without corrosion inhibitor has corroded on the total surface, while surface corrosion could be clearly reduced to up to 10-20% in the case of the addition of copolymers according to the invention.

Table 1: List of results in the Acronal® Optive 410 saline enamel spray test

Blank test

1st polymer 1b polymer 2nd polymer 2b polymer Polymer 3

Polymer corrosion inhibitor

null AN / IS / S (35/15/50) AN / IS / S (35/15/50) AN / IS / S (50/20/30) AN / IS / S (50/20/30) AN / IS / S (20/40/40)

Layer Thickness [µm]

67-82 66-82 66-75 66-81 68-81 67-88

Bubbles in the crack [mm]

7.7-edge 0-edge 0-edge 0-18.3 0-11.3 0-6.0

Crack adhesion removal [mm]

5.0-9.0 and bubbles 2.0-9.0 and bubbles 1.6-10.6 and bubbles 1.0-9.8 0.5-4.0 0

Lower crack oxidation [mm]

1.6-4.9 0-1.0 0-0.5 0-3.2 1.0-2.8 0

AN: acrylonitrile, IS: itaconic acid, S: styrene

Table 2: List of results in the Acronal® S 790 enamel salt spray test

Blank test

1st polymer 1b polymer 2nd polymer 2b polymer Polymer 3

Polymer corrosion inhibitor

null AN / IS / S (35/15/50) AN / IS / S (35/15/50) AN / IS / S (50/20/30) AN / IS / S (50/20/30) AN / IS / S (20/40/40)

Layer Thickness [µm]

68-78 64-77 72-85 64-71 65-74 68-76

Surface corrosion

100% Approx. twenty % Approx. twenty % Approx. 10% Approx. 80% Approx. 10%

Reticular cut after saline spray test

Gt 5 Gt 0 Gt 0 Gt 0 Gt 5 Gt 0

AN: acrylonitrile, IS: itaconic acid, S: styrene

Table 3: List of results in the enamel salt spray test based on the laboratory sample

Comparative

Polymer 3 4th polymer 4b polymer 4c polymer 5a polymer Polymer 5b Polymer 7

Layer Thickness [µm]

65-79 66-81 65-78 71-88 69-81 69-88 66-78 69-80

Lower crack oxidation [mm]

2-25 and bubbles 1-7 and bubbles 5-25 2-25 1-25 9-24 2-19 2-13

Surface corrosion

55% 13% 30% 27% 22% fifty % fifteen % 27%

AN: acrylonitrile, IS: itaconic acid, S: styrene

Claims (15)

1.-Procedure for the application of anticorrosive layers on metal surfaces, in which a hardenable preparation under atmospheric conditions in a thickness of at least 15 µm is applied on the bare metal surface, or containing the preparation at least

-

 15 to 70% by weight of at least one hardenable binder agent system (A) under atmospheric conditions,

-

 1 to 70% by weight of at least one component (B), selected from the group of finely divided fillers, pigments or dyes,

-

 0.1 to 40% by weight of a polymer anti-corrosion agent (C), as well as

-

 5 to 83.9% by weight of at least one solvent (D),

the amounts referring respectively to the total amount of components of the formulation, and in the case of the polymer anti-corrosion system of a copolymer (C), which is constituted by the following monomer components: (C1) 5 to 60% by weight of at least one monomer with monoethylenic unsaturation, which has at least one, preferably exactly one nitrile group, (C2) 10 to 70% by weight of at least one monomer with monoethylenic unsaturation, comprising at least one acidic group, (C3) 20 to 80% by weight of at least one aromatic hydrocarbon with monoethylenic unsaturation, as well as (C4) optionally 0 to 25% by weight of other monomers with ethylenic unsaturation other than (C1) to (C3), the amount referring respectively to the total amount of monomeric structural units in the copolymer, and subsequent hardening of the layer applied under atmospheric conditions, atmospheric conditions being understood as hardening temperatures of more than 0 to 40 ° C in the presence of air, and a relative humidity of 10 to 80%. 2. Method according to claim 1, characterized in that in the case of monomer (C1) it is acrylonitrile. 3. Method according to claim 1 or 2, characterized in that in the case of the monomer (C3) it is styrene. 4. Method according to one of claims 1 to 3, characterized in that in the case of the monomer (C2) it is itaconic acid. 5. Method according to one of claims 1 to 4, characterized in that the acid groups can be completely or partially neutralized. 6. Method according to one of claims 1 to 5, characterized in that the amount of monomer (C1) amounts to 5 to 45% by weight, of monomer (C2) to 15 to 60% by weight, and of monomer (C3) at 30 to 70% by weight. 7. Method according to one of claims 1 to 6, characterized in that at least one monomer (C4) is present in an amount of 0.1 to 25% by weight. 8. Method according to claim 7, characterized in that in the case of the monomer (C4) it is a monomer comprising OH groups, with monoethylenic unsaturation. 9. Method according to one of claims 1 to 8, characterized in that in the case of the metal surface it is the surface of steel, zinc or zinc alloys, aluminum or aluminum alloys. 10. Process according to one of claims 1 to 3, characterized in that in the case of the acid groups of the monomer (C2) it is carboxyl groups and / or sulfonic acid groups. Method according to one of the preceding claims, characterized in that in the case of the binder agent system it is at least one selected from the group of aqueous or predominantly aqueous dispersions of polyacrylates, or styrene-acrylate copolymers (A1 ), polymers of styrenealkadiene (A2), polyurethanes (A3) or alkyd resins (A4). 12. Method according to one of the preceding claims, characterized in that it concerns the surfaces of metal buildings or metal constructions. 13. Method according to claim 12, characterized in that it is the surface of buildings, bridges, electric poles, tanks, containers, buildings, pipelines, thermal power plants, chemical installations, ships, 5 cranes, palisades, sheet piles, reinforcements, pipes , tanks, tube fittings, flanges, couplings, ships, roofs and construction steel. 14. Method according to one of the preceding claims, characterized in that the layer thickness of the hardened layer amounts to at least 25 µm. 15.- Prepared for the application of anticorrosive layers on metal surfaces for protection against atmospheric corrosion, which comprises at least the following components:

(TO)

 15 to 70% by weight of at least one hardenable binder agent system (A) under atmospheric conditions according to claim 11,

(B)

 1 to 70% by weight of at least one component (B), selected from the group of finely divided fillers, pigments or dyes,

15 (C) 0.1 to 40% by weight of copolymer (C) according to one of claims 1 to 8 or 10, as well as (D) 5 to 83.9% by weight of at least one solvent (D), referring the amounts respectively to the total amount of components of the formulation.